Microstructure Characterization and Mechanical Properties of TiSi2-SiC-Ti3SiC2 Composites Prepared by Spark Plasma Sintering

Dense TiSi2-SiC and TiSi2-SiC-Ti3SiC2 composites in which SiC particles in 200-300 nm disperse, were reactively synthesized through spark plasma sintering (SPS) technique using TiC, Si, and C powders in micrometer as starting reactants. The phase constituents and microstructures of the samples were analyzed by X-ray diffraction, field emission scanning electron microscopy and transmission emission microscopy. The hardness, fracture toughness and bending strength of TiSi2-SiC and TiSi2-SiC-Ti3SiC2 composites were tested at room temperature. The fracture toughness and bending strength of TiSi2-SiC-Ti3SiC2 composites reach 5.4(plus-minus) 0.3 MPa·m1/2 and 700(plus-minus) 50 MPa, respectively. The factors leading to the improvement of the mechanical properties were discussed.